Colorimetric detection of platinum (IV) ions based on triangular silver nanoprism particles in aqueous environmental sample

Silver nitrate (AgNO₃), trisodium citrate dihydrate (C₆H₅Na₃O₇ · 2H₂O), sodium borohydride (NaBH₄), and L-ascorbic acid (C₆H₈O₆) were combined in distilled water to create a triangular silver nanoprism particle (AgNPRP) solution. UV-visible (UV-vis) spectroscopy at wavelengths of 350–460 nm and 580–700 nm was observed, and as a result of them, the successful formation of the triangular AgNPRPs was confirmed. The prepared silver nanoprism particles were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy(SEM), and transmission electron microscopy(TEM) and employed for the colorimetric detection of platinum(IV) ions in an aqueous solution containing Pt⁴⁺ ions. The color of the aqueous silver nanoprism particle solution, containing Pt⁴⁺ ions, changed from blue to light brown before turning colorless. Using UV-vis spectrophotometry, the detection limit of the Pt⁴⁺ ion concentration was determined to be 6.23 μM in an aqueous solution of silver nanoprism particles. The proposed method was applied for detecting Pt⁴⁺ ions in tap water samples.